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A Note About Website Navigation

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For users of screen readers, depending on the screen resolution, the two checkboxes are for opening and closing the side menus that appear to the left and right side of the screen. This is designed both for large screens and for mobile devices with a touch screen. Checking either the main menu or sidebar checkboxes causes the menu to open from the left or right side of the screen, respectively. Clearing the checkox in either the main menu or sidebar closes the menu. The checkboxes are visible to screen readers such as JAWS and NVDA for Windows, Voiceover for Mac, and Orca screen reader for Linux. When a screen reader says "clickable" for both main menu and sidebar, that is for the respective checkboxes. End of explaination.

Category: Networking, subcategory of The World of Computers

Backup Your WordPress or ClassicPress Files, Configuration, and Database with a Single Script

Audience and Prerequisites

Skip to scenario if you want to jump into the main article.

This is for anyone who currently host their WordPress or ClassicPress in a virtual private server such as DigitalOcean, Linode, or any other VPS providers. Any Linux user with knowledge of command line can perform backups and restoration tasks. You must be familiar with Linux and you know how to connect to your production server via SSH.

Plus, this article assumes that you have installed and configured WordPress in your VPS server. In addition, this article assumes you can perform basic database administration tasks such as adding a new database along with creating a new user for WordPress or ClassicPress. If your hosting provider provides managed WordPress or ClassicPress hosting, then this article may not apply to you. And because this article is for those who currently run a VPS server, I am going to have to assume that you have some hands-on experience with the Linux command line. This article need not apply to non-technical Linux, Mac, and Windows users. When I say non-technical Linux users, I'm talking about those who wanted to get away from Windows or Mac and simply wanted to use Linux just to browse the Internet and not deal with the command line.

Last, but not least, I am also going to assume that you know how to configure your Apache server as well. Both Apache and NGINX (pronounced Engine-X) configurations won't be covered here, including backing up and copying certificates that you get from your hosting provider.

If you are interested in learning Linux, a tutorial from Guru99 will help get you started on learning Linux.

Are you ready? Then let's get started!

Scenario

You have your own VPS server that is running ClassicPress. Your domain name is exmaple.com and your SSH port number is (insert your TCP port number here). You have a development server for developing your own custom ClassicPress theme and you want to use your development server to backup everything from your production server.


Article published: 2022-11-17 08:47

Categories: The World of Computers, Information Technology, Internet, Networking, Scripting and Programming

Pro Tip for Proxmox Users: Need to Add Multiple IP Addresses for a Single NIC in LXC?

A Note About Proxmox and LXC (Linux Containers)

For those unfamiliar with LXC and Proxmox, LXC is similar to a virtual machine that runs a guest OS (Windows, Linux, Mac, Android, etc.) but the container part of LXC excludes the core part of the OS and simply provides networking and storage inside a container. Unlike virtual machines, applications inside a container can access resources on a host system directly. Proxmox is a hypervisor for running virtual machines and Linux containers (LXC) in a server hardware.

IP Addresses and Subnetting

Do you need to have multiple IP addresses assigned to a network interface inside an LXC container? In terms of networking, a single NIC can have multiple IP addresses. This is useful if you want to run a single server with multiple websites that have their own IP address. Here's what I mean:

172.20.31.0/23
A small HTML file with a list of websites hosted by the web server.
172.20.31.1/23
A web application running Adminer, a lightweight alternative to phpMyAdmin.
172.20.31.2/23
A development version of my website that mirrors a production version. Anyone who visits my site sees my production version of my website. Once I test the changes I made in the development website, I push the changes up to the production website.
172.20.31.3/23
A custom-built web application for taking notes. Any notes written in HTML gets shown up in the web browser.
172.20.31.4/23
A development version of the note-taking web application taken from 172.20.31.3.

A note for those new to networking: pay attention to the subnet. A slash 23 subnet can start with 172.20.30.1 and ends at 172.20.31.254. Both 172.20.30.255 and 172.20.31.0 are both valid IP addresses. 172.20.30.0 is a network address and 172.20.31.255 is a broadcast address. Cisco has an article about IP addressing and subnetting in order to help you understand how subnetting works. With that out of the way, let's get into configuring a Linux container running in a Proxmox server.


Article published: 2022-06-21 20:22

Categories: The World of Computers, Networking

My Dream Home of the Future: Computer in Server Closet; KVM in Home Office; Home Theater

Home Theater made in Blender with 3 chairs and cup holders between chairs
This is a rendering of my home theater made in Blender. It has a 200" projection screen, 7.2.4-channel speaker system, and comfy seats with cupholders in between.

I have been watching a couple of YouTube videos of people who want a computer in one room (such as a wiring closet) and a keyboard, video, and mouse (KVM) in a home office. To give you an idea of what I'm talking about, I want to post links to YouTube videos.

Embedding YouTube or Odysee videos will insert a tracking cookie in users' personal computers. As a citizen of the US, I need to follow GDPR if European visitors visit my website. I don't like and want to talk to lawyers to be honest. 🤣😀

As for the video from Linus Tech Tips, I would much rather have a couple of computers rather than single computer that can house a couple of virtual machines running desktop OSes such as Linux and Windows just to make it easier for me. So yeah, a virtual machine is a computer within a computer that can serve different purposes such as running Ubuntu within Windows using VirtualBox or by running Windows OS in a Linux host using KVM or Xen.


Article published: 2021-08-14 17:42

Categories: Dreams and Imagination, Homes and Buildings, Home Theater, The World of Computers, Computers, Networking

How To Create a New User in pfSense and VyOS?

When you setup your new router, it's always a good idea to create a new user other than admin for pfSense and vyos for VyOS in order to reduce the chance that bots and miscreants will gain access to your router.

VyOS

Here's the completed configuration of my VyOS router and I will show you the commands.

Configuration
service {
    # ...
    ssh {
        access-control {
            allow {
                user <username>
                user vyos
            }
        }
        listen-address 10.249.0.1
    }
}
system {
    # ...
    login {
        banner {
            pre-login "Unauthorized access is strictly prohibited."
        }
        user <username> {
            authentication {
                encrypted-password ****************
                plaintext-password ****************
            }
            full-name "First and last name goes here."
            home-directory /home/<username>
        }
        user vyos {
            authentication {
                encrypted-password ****************
                plaintext-password ****************
            }
        }
    }
# ...
}
Commands
ssh vyos@10.249.0.1
configure
edit system login user <username>
set authentication plaintext-password <your-password-goes-here>
set full-name "First and last name goes here."
set home-directory /home/<username>
exit
edit service ssh access-control
set allow user <username>
set allow user vyos
commit
save

You want to allow vyos access using SSH to make sure it works. Also, there is encrypted-password in VyOS but VyOS gave me an error telling me that the encrypted password is invalid. I did try to discard, but VyOS told me there are not changes to be discarded, so I saved, started a new terminal window, and once I SSH into my VyOS router for 10.249.1.1, everything works fine.

Now don't exit out of VyOS session just yet. You want to make sure SSH is working properly for a user you want to log into. Because otherwise editing and viewing the configuration will have to be done either through the use of a console cable or a monitor and keyboard hooked up to a monitor. SSH using your new username and password you've created. If you can successfully login to VyOS with a different username, you can simply remove the vyos user from the access control list in configuration mode.

delete service ssh access-control allow user vyos

Again, stay logged in to VyOS and use a different terminal to test and make sure you can log into VyOS through SSH. If everything is working as intended, you can safely log out of VyOS from all the terminals you've opened.

Also, you can configure a banner. Examine the configuration above and see if you can add a login banner. The pre-login is for when a user attempts to access the VyOS router using SSH. This will print out a banner before a user gets prompted for a password. After a user logs into VyOS, if the post-login is set, VyOS will print out the banner once the user logs in. This concludes the commands used for securing VyOS.

pfSense

The same can be done for pfSense. Open the web browser, point your browser to pfSense (in my case, http://10.249.2.1), and login to your pfSense web interface. Once you get to the main interface, follow instructions as follows.
  1. In the System menu, open the User Manager.
  2. Click in the + Add button below the list of users.
  3. Enter the Username, Password, and Full Name. No spaces in the username.
  4. In the Group Membership area, select admins and click in Move to "member of" list. This will move the admins group to the "member of" list.
  5. Save the changes, log out, and log back in as the new admin user you have created in step 4.
  6. In the user manager, click in the pencil icon (Edit) to edit the admin user.
  7. Check the checkbox for Disabled. An admin user cannot login once the checkbox is selected.
  8. When done, Save the changes.

Try to login as admin. If successful, you should not be able to log in as an admin user but instead log in as a new user. This concludes the step-by-step instructions for pfSense.

Conclusion

Preventing a root or admin user from logging into a router is one of the security's best practices. You can help ensure that bots and miscreants won't be able to gain access to your router without the correct username and password. Even when bots are performing a brute-force attack. Still, it's important to restrict access to the router through the use of a management subnet and if using pfSense, setup a root and server certificate in the Cert. Manager within the System menu and add a root certificate to your web browser of your choice. Use a management subnet for any devices that have SSH access or a web interface and do not allow managers, sales, web developers, or any other non-IT departments access to the critical network infrastructure.

Update: I just hit "c" twice in my keyboard (ccode instead of code) even though I only typed "c" just once. Ugh... Maybe I just need a different keyboard that prevents double-types regardless of the operating system I'm using... (And yes, I'm using Arch Linux.)


Article published: 2021-02-25 21:04

Categories: The World of Computers, Networking

IPv4 Subnetting Practice

If you understand computer networking and know how IPv4 subnetting works, here's a zip file which contains a self-contained HTML file. Double-click in the HTML file and you can begin practicing.

ipv4subnet.zip

Have fun!


Article published: 2021-02-12 22:47

Categories: The World of Computers, Networking

Part 1: OSPF (IPv4) - Connecting 2 Instances of VyOS and pfSense Together

This is part 1 of 2 of configuring multiple networks that can communicate with each other through OSPF.

Introduction

How much do you know computer networking? Do you know how subnetting works? What about IP addresses? Do you know how routers and switches work? Do you have a homelab and do you know what a homelab is? If you answer yes to all of the questions and you want to expand your knowledge of networking, this article is for you. Yes, I'm targeting audience that have a good knowledge in networking. This is even for those with lack of certificates such as CompTIA A+, Network+, and Security+, and even for those without a degree! Well, why don't we delve right into it, shall we? If you are Network+ certified, you must know that OSPF is a dynamic link-state protocol that allows the two or more private networks to talk to each other. If you have a consumer router such as Netgear or Linksys, this article is only for the pros!

Also, my article covers the use of virtual machines and networking bridging, so I'm going to assume you know how to set them up. I'm using Ubuntu Server 20.10 as my Linux home server that runs KVM (Kernel-based Virtual Machine). Virtual machines are what enables a computer to run inside a computer and network bridging behaves similar to a network switch. And because of that, I'm also going to assume you are familiar with the Linux command line.

Now buckle your seatbelt because this article is going to be a very long one.


Article published: 2021-02-08 00:03

Categories: The World of Computers, Networking